Moisture sealing wall tile



April 5, r I M. MACCAFERRI 2,880,607

MOISTURE SEALING WALL. TILE Fil9d Sept. 11, 1957 2 Sheets-Sheet l 5 20 E '2' M T 22 3| zla/lu V V ,42 5 5555 55 5 55555555 M. MACCAFERRI 2,880,607

MOISTURE SEALING WALL TILE April 7, 1959 2 Sheets-Sheet 2 Filed Sept. 11, 1957 I ATTORNEYS United States Patent MOISTURE SEALING WALL TILE Mario Maccaferri, Rye, N.Y.

Application September 11, 1957, Serial No. 683,275

Claims. (Cl. 72-18) My invention relates to certain improvements in moisture sealing wall tiles of the plastic types adapted to be installed by hand-pressing into installed position against a mastic or cement coating on the surface to be covered by the tiles; and the nature and objects of the invention will be readily recognized and understood by those skilled in the art to which the invention relates from the following detailed description and explanation of the accompanying drawings illustrating several embodiments or structural expressions of the invention from among various other forms, embodiments, expressions and constructions of which the invention is capable within the broad spirit and scope thereof as defined by the claims hereto appended.

Plastic wall tiles of the types with which my present invention is primarily concerned are comprised of relatively thin light-weight plastic material bodies of general plate form having rearwardly extending flanges completely around their outer edges with the rear edges of such flanges forming seats for engagement with the surface on which the tile is installed to properly position the tile with the major area of its body spaced from the surface of installation. In the installation of such tiles the surface on which they are to be mounted is usually covered with a relatively thin coating of mastic or cement which adheres to such surface and the tiles are then handpressed onto the surface against and in contact with the mastic coating so that the tile is held and maintained in installed position by adherence to the mastic or cement. As these plastic wall tiles are a quantity production article in a highly competitive market, production costs are critical, including such costs as the making of the molds, the molding, and. the quantity of material used per tile. It follows, therefore, that structural simplicity is essential from both the standpoint of the cost and maintenance of the mold and of the tile produced by the mold. Light weight is also of importance because, as pointed out above, such tiles are usually hand-installed by finger pressing them into position on the mastic coated surface which they are to cover so that they must be capable of being easily manually handled and manipulated for eflicient installation thereof. And as the plastic raw material from which the tiles are molded is an important factor in the cost of the finished tiles it follows that a light weight tile reduces such cost factor.

When these plastic tiles are installed in position by adherence to a mastic or cement coating on the surface covered thereby, a serious problem is encountered due to moisture seepage from around the edges thereof through the joints between adjacent tiles and under the tile flanges to the rear surface of the tile. This problem is aggravated by the fact that plastic tile installations are usually cleaned by using damp cloths and by the further fact that such installations are generally used for shower stalls, on bathroom walls and in kitchens. where they are subject to direct application of water and/or air with high moisture content. It is found that if moisture gains access to the rear surface of one of these ice 2. masticv or cement-installed tiles, that is, between the rear surface of the tile and the mastic or cement, then frequently the adhesion of the tile to the cement isbroken and the tile either becomes displaced from position relative to and properly aligned with. adjoining tiles or falls or drops completely from installed position. In. either event. the appearance and effectiveness of the tile installa tion is substantially impaired.

In the manufacture and the distribution of. such. plastic wall tiles it is general practice throughout the industry to pack the tiles in relatively loose stacks in a carton or other suitable container with the tiles in each. stack made up of pairs of tiles placed back-to-back. With these tiles constructed as they are of a. body in plate form. with the rearwardly extending edge flanges therearound, when the tiles are stacked in back-to-back pairs, the finished and ornamental front face surfaces of the tiles of each pair are in direct contact and engagement with. the ornamental front face surfaces of tiles of the adjacent pairs in the stack. As the tiles are relatively loosely packed in. such stacks, it has been found that the forces to which the cartons of tiles are subjected in handling and transportation cause relative movements between the tiles and the pairs thereof so that surface marring, abrasion or scoring of the directly engaged front or face surfaces of the tiles frequently results. This highly undesirable result is further aggravated by the fact that due. to such relative movements between tiles of a back to-back pair, one of the tiles of a pair will frequently become canted or tilted relative to the other tile of that pair and to the adjacent tile engaged thereby of the pair adjacent thereto in the stack of back-to-back pairs of tiles. Such a canted tile may become locked in its canted or tilted position due to engagement between the flanges of the tiles, so that the tiles cannot restore themselves from such a canted or tilted position to their normal generally parallel relationship. The foregoing conditions have been the primary cause for substantial rejections and returns of marred or scored tiles with the consequent economic loss to the manufacturer whois forced to replace such rejected tiles with perfect ones.

In addition to the'foregoing problem of tile face disfiguring due to marring or scoring of engaged tile face surfaces by relative movements between the tiles of? a stack thereof, another problem. is encountered due to the fact that the tiles have bodies which are quite thin and which, when the tiles are stacked in back-to-back pairs with the edge flanges in engagement, have the major area thereof between the flanges unsupported against lateral springing, bending or inward deflection under compressive forces which may be applied to the front or face sides thereof. These tiles with their thin. bodies. are subject to fracture or. cracking by compressive forces applied thereto in a direction to centrally depress the thin body if not properly supported over at least the central area of the body and between. the flanges of the tile.

My present invention has as. a general. object. the provision of. a design and construction. of. plastic wall tile in Which the foregoing problems. of. moisture seepage to the rear of installed tiles, as Well. as ofv tile face mar:- ring or disfiguring and of tile body factureof. packed. tiles in transportation and handling; are substantially elirrrinated.

It is a further object to provide for the substantial elimination of the foregoing problems by a design and con: struction. which is simple yet highly eflicient and effective without. substantial increase in mold complication or cost and. without adding substantially to the. quantity of material or resulting weight of the tile, so that. the tile can be produced in quantity on a competitive cost basis. i

' Another Object is to provide a system of intersecting or mesh arrangement of sealing ribs around the outer marginal portion of the rear surface of the tile extending from the tile edge flange for a short distance inwardly therefrom so that a continuous band or panel of such intersecting ribs is provided with multiple points of rib intersection to thus effectively reduce seepage or entry of moisture therepast from under the edge flange of the tile to the major area of the rear surface thereof.

Another object is to so design and construct such arrangement of intersecting or mesh ribs that they will also effectively function as guide ribs to prevent interlocking between the edge flanges and particularly the corner portions of such flanges of a pair of such tiles "placed back-to-back, as well as to serve as friction reducing means so that the frictional forces acting to prevent the movement of the backs of the tile over each other are reduced to less than the total of the frictional forces and the static forces acting to prevent sliding movement between engaged front face surfaces of the tiles of a pair of back-to-back tiles and the tiles of the adjacent back-to-back tiles in a stack of such tiles. Another object is to provide a system and arrangement of relatively short, angularly positioned support ridges or ribs spaced apart on and extending rearwardly from the rear surface of the tile by which such support ribs with the tile placed back-to-back with another tile having such system of support ribs will always rest upon and angularly cross over the support ribs of the other tile in any position of plan or flange to flange alignment of the back-to-back tiles.

With the foregoing and various other objects, advantages and results in view, which will be readily apparent and recognized from the following detailed description and explanation, my invention consists in certain novel features in design and construction and in relationship and combinations of parts and elements, all as will be more fully set forth and specified hereinafter.

Q Referring to the accompanying drawings in which similar reference characters refer to corresponding parts and elements throughout the several figures thereof:

Fig. l is a view in plan of the rear or under side of a plastic wall tile embodying my present invention in a preferred form thereof.

Fig. 2 is a transverse vertical sectional view through the tile of Fig. 1, taken as on the line 22 of Fig. 1.

' Fig. 3 is a fragmentary view in top plan of a tile of Fig. 1 showing the beveled or rearwardly inclined front face of the marginal portion of the tile and including a corner of the tile.

7 Fig. 4 is an enlarged rear plan view of a corner portion of the tile of Fig. 1 showing the arrangement of corner sealing ribs.

Fig. 5 is an enlarged transverse section through the mesh" sealing rib system of the tile of Fig. 1, taken as on the line 5-5 of Fig. 4, and showing particularly the panel surface and integral sealing ribs thereon along the under side of the marginal portion of the tile.

Fig. 6 is a plan view of a pair of tiles of Fig. 1 in back-to-back relation and showing by dotted lines the tile body support ribs in their engaged, angular and intersecting relationship supporting the tile bodies against inward springing or depression relative to each other.

Fig. 7 is a diagrammatic view of a tile in rear plan having a modified arrangement of body support ribs in which the ribs are in parallel relation to the adjacent edge flanges, respectively, of the tile.

Fig. 8 is a diagrammatic view in rear plan showing an arrangement of the body support ribs of Fig. 1 reversed in positions on the rear side of the tile.

Fig. 9 is a view, more or less diagrammatic, in rear plan of a portion of a tile embodying a modified form and arrangement of sealing ribs of my invention in which the intersecting, mesh forming ribs are arcuate in form.

A standard size of plastic wall tile T formed in this instance of a suitable polystyrene composition, and incorporating and embodying a design and construction in accordance with the principles of my invention, has been selected as an example and is illustrated in Fig. 1, in connection with Figs. 2 through 6, of the accompanying drawings. This example tile T is of square plan form of 4%" by 4%" dimensions with the body B thereof of plate form of a thickness of the order of 0.062", that is, approximately The body B provides the front or face side 10 having the finished, ornamental front face surface 11, and the rear side 12 having the rear surface 14 over the major area thereof generally parallel with the front face surface 11. The body B of the tile T has a marginal portion completely therearound identified generally by the reference character M. This marginal portion M on the front side is beveled, or preferably as here shown formed on a radius to incline outwardly and rearwardly to form the gently curved or sloping marginal edge portion 11a of the front face surface 11. (See Fig. 3.) The outer edges of the marginal portion M of tile T have integral therewith the rearwardly extending continuous edge flange therearound formed of an edge flange 20 along the outer edge of the marginal portion M of the tile body along each side thereof with these side edge flanges 20 integrally joined at the corners of the tile to form the flange corners 21 of the continuous rearwardly extending edge flange F. The side edge flanges 20 making up the continuous edge flange F of the tile T of this example have their rear edges 22 located in a common plane spaced a distance rearwardly from the plane of the major area of the rear surface 14 of the tile. In this specific instance the edge flanges 20 extend a distance rearwardly such that the overall thickness of the tile T from the plane of the front face 14 thereof to the common plane of the rear edges 22 of the side edge flanges 20 is of the order of 0.110, that is, slightly greater than approximately A The thickness or transverse width of the edge flange at the rear edges 22 thereof is of the order of 0.040.

In accordance with my invention as expressed herein by the example tile T, a planar panel surface 30 is formed on and along each side edge on the rear or under side of the marginal portion M of the tile body B extending along the full length of the adjacent edge flange 20. Each of these panels 30 joins at its opposite ends with and merges into the adjacent ends of the panels 30 along adjacent side edges of the tile body to form the panel corners 31 on a straight line disposed diagonally of the tile body from the edge flange corners 21. Thus there is formed by the four (4) panel surfaces 30 a continuous planar panel surface, identified generally by the reference character P, which extends completely around the rear side of the tile body under the marginal portion M thereof and along and extending inwardly from the continuous edge flange F formed by the side edge flanges 20. In the tile of the dimensions of tile T each planar panel surface 30 extends inwardly from the adjacent side edge flange with which it is integrally joined along its outer edge 32 in a plane spaced inwardly from the plane of the rear edge 22 of the adjacent edge flange 20 a distance equal to approximately or a distance of the order of approximately 0.030". Each planar panel surface 30 extends inwardly from its adjacent edge flange at an inclination to a plane normal or perpendicular to the general planes of the front surface 10 and rear surface 14 of approximately 15. The width of each of these planar panel surfaces 30 in the example tile T is approximately 1 or, of the order of approximately 0.25". Thus in clined inwardly from the edge flanges 20 to the rear surface 14 of the rear side 12 of the tile body B, each of these planar panel surfaces 30 smoothly merges and fairs into the rear surface 14 along the rear edges of the panel surfaces indicated by the lines 33, as will be clear by references'to Figs. 1 and 2 of the accompanying drawings in particular.

By my present invention I have provided an eflicient and effective system or arrangement of spaced but intersecting sealing ribs or ridges 40 and 41 on and disposed generally transversely across and completely occupying each planar panel surface 30 with such system of ribs or ridges 40 and 41 intersecting and joining over and across the corners 31 of the panel section to thereby provide a continuous and unbroken system of sealing ribs completely around the underside of the marginal por-.- tion M of the tile. The ribs 40 and 41 are integrally joined at their outer ends with the edge flanges 20 making upthe continuous edge flange F of the tile T. The system or arrangement of the intersecting sealing ribs or ridges 40 and 41, as expressed in this example, forms what may be aptly termed a mesh arrangement of crossed-over and integrally intersecting ribs providing along the length of each rib a plurality of points of intersection and integral joining with adjacent intersecting ribs to provide an effective and unbroken multiple barrier to seepage or passage of water or moisture thereacross to'the major area of the rear surface 14 of the tile body. And in addition to functioning as sealing ribs against passage of moisture, these ribs 40 and 41 are so arranged and interpositioned in their relationship to the rear surface ofv the tile body and to the edge flange 20 thereof that they also function to prevent interlocking between tiles of a back-to-back pair of tiles when one of the tiles of the pair becomes displaced fro-m proper aligned position with the other, as will be explained more fully hereafter.

My mesh system or arrangement o-f'sealing ribs in atile of 4% x 4%" plan dimensions of the example tile T, provides the first plurality of ribs or ridges 40 extending transversely across each planar panel surface 34) from and integral with the inner side of the adjacent edge flange 20 to the inner edge 33 of the panel where they merge at their ends into the surface 14. The ribs 40. are positioned on a panel 30 inclined at an angle of 4 to the adjacent edge flange 20 with the spacing between the ribs in this instance being approximately 4; or 0.125". This plurality of sealing ribs or ridges 40, each of which is inclined at an angle of 45 across a panel surface 30 has a length of approximately In this instance each ofv the ribs 49 has a width of approximately the order of A or slightly less, and each at its outer end 40a integrally joins with the adjacent edge flange 20 and has its rear edge surface at its integrally joined outer end 40a substantially in the plane of the rear edge surface 22 of the edge flanges 2t). Inthe example tile T'hereo-f, the rear edge 40!; of each of the ribs 40 extends inwardly therealong in substantially the planev of the rear edges 22 of the flanges 23 for a distance of approximately /8, and then inclines inwardly on a radius of approximately to the rear surface 14 of the rear side 12 of the tile with the inner end 40c of the rib merging into the rear. surface 14. (See Figs. 2 5).

The intersecting or mesh system or arrangement of the sealing ribs 40 and 41 is completed along the entire length of each planar panel surface 30 by the. second plurality of ribs or ridges 41 of identical dimensions with the dimensions of ribs 40 but extending from the adjacent edge flange 20 of a panel surface 30 at an inclination or angle of 45 in the direction reverse to the angle of inclination of the ribs 40. These ribs 41 are spaced A3." apart along the length of a panel surface 30 with their outer ends 41a integral with the edge flange 20 at and integral with the ends 40a of the adjacent rib 40, that is to say, the ends of adjacent reversely inclined ribs 40 and 41 form a common integral joint with an edge flange. 20. Except for the reverse angle of inclination, the. ribs 41 are identical with the ribs 40 and each has the rear edge surface 41b thereof in the plane of the rear.

edge 22 of the edge flange 20'with which joined, for a of each rib 41 from the position thereof in the planeof.

the rear edge surface of an edge flange. 2.0,; then inclines inwardly on a radius of. approximately to the rear surface 14 of the tile with the rear edge. 41c of the rib merging into the said rear surface of the tile. (See. Figs. 2 and 5).

With this arrangement orsystem of intersecting ribs and 41 it will be noted that: each rib 40 and each rib 41 is joined integrally at its outer end 40a and 41a.

with an edge flange 20 and extends inwardly therefrom and intersects two (2) of the oppositely inclined ribs 40 or 41 at the integral points of joinder 1 and 2, respectively. It follows, therefore, that with such sealing rib arrangement throughout the length, of a panel surface 30 along each side edge of the body B under the marginalv portion M thereof, there is a continuous and unbroken multiple barrier against the seepage or passage of moisture or water to the area of the rear surface 14 of the tile which is surrounded by such. intersecting mesh rib arrangement. This multiple barrier is provided by the integral joining of the outer ends 40a and 41a of the ribs 40 and 41 with the edge flange 20 and the integral points of intersection and joinder'l' and 2 of each' rib with two- (2) of the oppositely inclined ribs which cross. over, intersect, and are integrally joined with such firstmentic-ned rib.

The sealing rib system comprised essentially of the ribs 40 and 41, as hereinabove described and as disclosed particularly in Fig. 1 of the drawings, is completed at the corners of the continuous panel surface P- by providing in each corner thereof along the line of juncture 31 a diagonally disposedi rib 42 which is integral at its outer end 42a with the adjacent flange corner 21 and which extends inwardly to the corner formedby panel sections 30 and merges at its inner end 42b into the rear surface 14 of the tile. This rib has the general width or thickness dimensions of the ribs 40 and 41 and has the rear surface at its outer end 42a substantially in the plane of the rear edges 22 of the edge flanges 20. Each of the corner ribs 42 has the rear surface 42c. thereof progressively inclined inwardly and forwardly from its outer end to its inner end 42b.

In'each corner of the continuous panel surface P on which the ribs 40 and 41 are integrally formed, there is provided an outer cross rib 43 which is bisected by and joins integrally with the corner rib 42, and which.

7 at its opposite ends integrally joins with the outer ends of the adjacent innermost ribs 40 and 41 of the mesh".'

system of ribs on the adjacent panel surfaces 30. An' intermediate cross rib 44 is provided spaced inwardly from the outer cross rib 43, across and'intersecting integrally the corner rib 42 and the adjacent ribs 40 and 41 on the adjacent panel surfaces 30 with the opposite ends of this intermediate cross rib. 44' integrally joined with the outer ends of the next adjacent ribs 40 and 41 of the adjacent panel surfaces 30. An inner cross rib 45 is formed integrally with the adjacent panel surfaces 30 spaced inwardly from the intermediate cross rib 44 and extends across and intersects the corner rib 43 and the next adjacent ribs 40 and 41 at each side of the corner rib. The opposite ends of this inner cross rib 45 are integrally joined with the adjacent edge flanges 20, respectively,'at the points of integral joining of the inner ends of the next adjacent ribs. 40 and 41 with the edge flanges 20. There is thus formed and provided. a complete and unbroken panel surface P" at the und'er side of the tile with such corner barrier arrangement joining in unbroken and continuous connection with the rib-system formed of the intersecting ribs 40 and 41 along the panel surfaces 30' adjacent tosuch corner.

A plastic wall tile incorporating the principles of: the intersecting or' mesh sealing rib system as above. des scribed, say, for example, the tile T'ofr this disclosure isi assessor installed in the usual manner familiar in the art by hand-pressing the tile on and against a mastic or cementcoated surface. Thus, when the tile is pressed into position in and against the mastic coating on the surface, the mesh" forming ribs 40 and 41 will be forced into the mastic with displacement of the latter into the cup-like spaces formed between the ribs 40 and 41 and the edge flanges 20 to thus form a complete and unbroken seal or barrier against entry of moisture to the rear surface 14 of the tile. Any water or moisture which enters between the joints between tiles of an installation and attempts to seep or move by capillary attraction or otherwise under the edges 22 of the edge flanges 20, in order to gain access to the rear surface 14 of the tile and between that surface and the engagnig surfaces of the mastic will be forced to follow the extremely tortuous path presented by the side surfaces and inner edge surfaces of the system of intersecting ribs 40 and 41 and between those surfaces and the mastic engaged therewith. Such tortuous path, with its abrupt angle changes of direction, effectively reduces moisture passage to the rear surface 14 of the tile surrounded by such rib system. Thus an efiective moisture sealing system for plastic wall tile is provided which does not require extreme mold complication and resulting costs, and further, which does not add materially to either the weight or the amount of material required for the tile or to the over-all thickness of the tile or to its plan dimensions.

It is to be understood that while the rib system of the example hereof provides the ribs thereof at 45 angles to the adjacent edge flanges, other angles may be used and within the principles of my invention the intersecting ribs need not necessarily in all instances have the same angle to the edge flange. And again, in what I now consider to be the preferred form and arrangement of these sealing ribs as illustrated by the tile T, it will be noted that the ribs 40 and 41 join the edge flanges 20 at the same point or in a common joint and that similarly, the ribs have common joining points along the inner edges 33 of the panel surfaces 30. However, if desired or found expedient in any particular instance, it is contemplated and intended that the ribs 40 and 41 join at their outer ends along the edge flanges 20 independently and spaced apart from each other and at their inner ends may similarly terminate and merge into the rear surface of the tile at independent points spaced from each other. The sealing rib system or mesh arrangement, as disclosed in the example tile T, and as preferred in order to carry out a further feature of the invention, provides the ribs 40 and 41 and the corner ribs 42 with their rear edges inclined inwardly on a radius of the order of from locations on the ribs spaced inwardly therealong a distance of approximately A" from the edge flanges 20 to the rear surface 14 of the tile into which the rear ends of the ribs merge, as hereinabove described and explained. However, while the specific construction of the ribs 40 and 41 of the example tile T may be preferred, the inclination of the rib rear edges need not be on a radius but may be a more or less planar inclination, and whether or not on a radius, may initiate at or immediately adjacent the rear edge of an edge flange 20 of the tile instead of a substantial distance, such as the /e" of the example, inwardly from the tile edge flange. The principle of my invention, however, is not in all respects limited to such construction and arrangement as, if desired, these sealing ribs may have a greatly reduced inward and forward inclination for their rear edge surfaces and thus maintain substantially throughout their length the depth thereof at the edge flanges. The essential and basic feature of this rib system is the provision of the multiplicity of relatively closely spaced and oppositely inclined sets of ribs extending inwardly integrally from the edge flanges for a distance over the rear surface of the tile body to form the continuous band, of intersecting ribs providing the unbroken multiple barrier against passage of moisture therepast which is to adhere it to the surface to be covered by the tile.

In addition to providing the effective seal or barrier against seepage or passage of moisture to the rear surface of a tile, the mesh system of intersecting ribs 40 and 41 and corner ribs 42, 43, 44 and 45 of the preferred form thereof of the example tile T, such ribs also function to substantially eliminate interlocking between the tiles of back-to-back pairs when a tile displaces from its normalposition of alignment and general parallelism with the other tile of the pair. With the ribs 40 and 41 having their rear edge surfaces 40b and 41b progressively inclined inwardly and forwardly to merge at their inner ends 40c and 41c smoothly into the rear surface 14 of the tile, when a tile of a back-to-back pair is displaced or slides from alignment with the other tile of the pair, these ribs 40 and 41 will be engaged by the displaced tile and will guide and restore the tile to its normal position of alignment without permitting the flange or sealing ribs of the displaced tile to interlock with the edge flanges or sealing ribs of the other tile of the pair. This is an important feature of my present invention because it eliminates the aggravated abrasion or marring which takes place between the engaged finished front face of a displaced tile which has become tilted or canted and the tile of an adjacent pair of back-to-back tiles in the usual packing arrangement thereof. Further, by such construction of the sealing ribs friction between back-toback tiles is reduced to a minimum and will be less than the total of the friction forces and the static forces existing and resisting relative movements between the engaged face surfaces of the tiles of a pair of back-to-back tiles and the tiles of adjacent pairs in a stack of such tiles. Thus any forces tending to displace tiles from their proper aligned positions in a stack will cause displacement between the back-to-back tiles rather than between tiles having their finished face surfaces in engagement.

The arrangement of intersecting, mesh forming sealing ribs embodying the principle of my present invention may instead of the straight rib form of the system of the example of Fig. 1, take the form of the plurality of intersecting arcuate ribs 70 as exemplified in Fig. 9 of the drawings. In the modified form of the invention of Fig. 9 each of the ribs 70 is formed on a radius as an arc of a circle with its opposite ends 7011 and 70b integrally joined with the inner side of the tile edge flange 20 with which the rib is associated. Each rib 70 ex tends inwardly from the edge flange 20 with which it is joined, a distance over and integral with the rear side 12 of the tile body. As indicated by Fig. 9, a plurality of the arcuate ribs 70 are located relatively closely spaced apart along each side edge flange 20 of a tile (portions only of adjacent edge flanges 20 being shown in Fig. 9) with the arcuate ribs integrally crossing over and intersecting each other to provide the sealing rib system having the multiple points of intersection be tween the edge flanges and the area of the rear side of tile surrounded by such rib system. In the illustrated adaptation of the modified rib system of Fig. 9, each side edge flange 20 forms in effect a chord of the circle from which each of the ribs 70 along such side edge is generated. The radii on which the arcuate ribs 70 are formed and the spacing from an edge flange 20 of the centers about which the ribs are generated, effectively determine both the spacing along the edge flange between the rib ends 70a and 70b, and the distance which the ribs extend inwardly on the rear side 12 of a tile body.

With the system of arcuate sealing ribs 70 of the modification of Fig. 9, the innermost ribs at each corner are joined to provide the single rib 71 which extends into the corner of the edge flanges 20 to form in efiect a diagonal corner rib which branches at its outer end into the adjacent inner ribs 70 of the system of ribs 9 along the adjacent side edge flanges which meet at such corner of the tile. And if desired the additional arcuate corner ribs 72 may be provided extending from adjacent side edge flanges 20, respectively, inwardly across the corner rib 71 and adjacent ribs 70 of the rib system along each side edge flange.

Preferably the outer ends of the arcuate' ribs 70 have their outer or rear edge surfaces substantially in the plane of the rear edges or the edge flanges 20, from the outer ends 76a and 70b thereof a distance inwardly therealong, and then either on a radius or on a straightline incline inwardly to the rear surface 14 of the tile where they merge into such rear surface. In other words the depth or thickness of a rib decreases from its maximum at the outer end portions thereof to substantially zero thickness at its innermost, central portion 70c. If desired such inward inclination may not extend in such degree as to merge the inner centralportion 70c ofa rib 70 into the rear surface 14 of the tile, or, the ribs may eliminate such inward inclination and have their entire rear edge surfaces located substantially in the plane of the rear edges of the edge flanges 20. The foregoing constructions of the arcuate ribs 70 apply also to and may be followed, as elected, to the corner ribs 71 and 72.

Plastic wall tiles of the type having the rearwardly extending edge flange, such as the flange F of the example tile T hereof, present basically an unsupported major area of the tile body B across and between the flange F when the tile is supported in position: on the.

rear. edge surfaces 22 of the. flange. Whenv tiles of this type are packed for transportation, storage and distribution in the stacks of back-to-back pairs, as hereinbefore referred to and described, the major areas of thebodies of the tiles are unsupported with thetiles finding only support along and around the aligned and meeting. rear edges of their edge flanges. These tiles with their very thin bodies are subject to fracture or cracking if overloaded in compression, and particularly if the compressive forces are applied to the central portion of the unsupported body. Thus when packed in back-to-back pairs in a stack, any compressive forces applied to the sides of the the at one end of the pack will tend to depress or displace the bodies of the back-to-back tiles inwardly toward each other with possible damage to the tiles. Similarly, when the tiles are installed by pressing onto the mastic coated surfaces excessive compressive forces may be applied with resulting possible fracture or cracking of a tile. While plastic wall tiles of commerce are frequently provided with various arrangements of projections. or ribs on the rear surfaces thereof between the surrounding edge flanges, these projections or ribs are. not effective in properly supporting and preventing excessive inward springing or depressing of the bodies of the tiles between the edge flanges when the tiles are assembled and packed in back-to-back pairs.

A basically important feature of my present invention is. to provide an effective system of support ribs or ridges spaced over and projecting rearwardly from the rear surface of the body of a tile between the surrounding edge flange, and to so relatively arrange and position such support ribs that when tiles provided therewith are placed back-to-back in edge flange alignment and abutment, the support ribs of one tile will always cross over and have direct transverse bearing on and across the support ribs ofthe other tile. Thus, in back-to-back relation the tile bodies between the surrounding edge flanges are always completely rigidly supported against inward springing or depression by compressive forces applied to the outer sides of the tiles acting inwardly thereon.

A preferredsystem and arrangement of such support ribs or ridges of my invention is disclosed in Fig. 1 in connection with Figs. 1 and 6. Referring to Fig. 1, support ribs or ridges 51, 52, 53 and 54 are provided projecting rearwarclly from. the rear surface 14 of the tile T in a specific angular relationship spaced apart over the major areaof such rear surface. In this example, except for the angular relationship of these support ribs 51 through 54, each rib is identical and for a tile of the dimensions ofthe tile T hereof has a length of approxi mately and a width or thickness of approximately the order of or slightly less. Each of the support ribs 51, 52, 53 and 54 of such dimensions has its rear edge formed on a radius from end-to-end thereof, that is, the outer edge contour of each support rib is arcuate longitudinally or lengthwise of the rib. These support ribs 51 through 54 are molded or otherwiseformed integral with and in a plane substantially normal to the plane of the rear surface 14 of the tile.

In the preferred form and arrangement of the support rib system of my invention of the example tile T hereof, four (4) sets of support ribs 51, 52, 53 and 54 are provided with the support ribs of each of these sets located in specific angular positions relative to the edge flanges 20 of the tile in a quarter section of the area of the rear surface 14 of the tile in which the set is located. When facing Fig. 1, that is, when facing a tile T with its under or rear side 12 turned upwardly, one set of support ribs' is positioned and located in the lower left-hand quarter section identified as K; another set of the support ribs is positioned in the lower right-hand quarter section identified as L; another set in the upper left-hand quarter section identified as M; and another set in the upper right-hand quarter section identified as N, of the rear surface 14 of the tile.

Each of the sets of support ribs 51, 52, 53 and 54 in a quarter section of the rear surface of the tile 14, is identical and the support ribs of each set are identically angularly positioned with respect to the portions of theadjacent edge flanges 20 of the tile T at that quarter section as the support ribs of each of the other quarter sections. First taking the set of support ribs in the lower left-hand quarter section K of the tile T when facing Fig. 1, the outermost lower rib 51 is positioned at an angle of approximately 15 relative to the left-hand side edge flange 2t and inclines at this angle upwardly in a:

direction fro-m the lower side edge flange 20 toward the left-hand edge flange 20. inner end of support rib 51 is spaced approximately /8 from the inner edge 33 of the panel surface 30 along the lower side of the tile while the upper end of this rib is spaced approximately /2 from the left-hand side edge flange 2t). The inner and lower support rib 52 is likewisepositioned at an angle of approximately 15 to the lefthand side edge flange 2t) but is inclined in the direction the reverse of the direction of inclination of the outer rib 51. The inner end of the rib 52 is' spaced from the inner end of the rib 51 a distance of approximately /8 while the outer, that is the lower end of rib 52, is spacedfrom the inner edge 33 of the lower panel surface 30 a distance of approximately A3. The upper left-hand support rib 53 is positioned at an angle of approximately 45 to the edge flange 20 at the left-hand side of the wall and has its outer end spaced a distance of approximately /2" from the inner edge 33 of the panel section 30 along said left-hand side of the tile. The lower end of the support rib 53 is spaced a distance of approximately from the lower end of the support rib 51. The inner, upper support rib 54 which completes the set of support ribs in the lower left-hand quarter section K of the rearsurface 14 of tile T is positioned at an angle of approximately 15 to the left-hand edge flange 20 and inclines in a direction upwardly and outwardly from the lower edge flange 29 toward the left-hand edge flange 20. The'outer' end of the support rib S4 is spaced from the outer end of the support rib 52 therebelow a distance of approximately and is spaced inwardly from the inner end of support rib 53 a distance of approximately /s".

Each of the sets of supporting ribs 51, 52, 53 and 54- in each of the other quarter sections K, L, M and Not In this specific instance the till the rear surface 14 of the tile T has the support ribs thereof arranged identically with the arrangement of the ribs above described in the lower left-hand quarter section K of the tile when facing the rear side of the tile in the position of Fig. 1. if the tile is rotated clockwise from the position of Fig. 1, through 90 so that the lower right-hand quarter section L is then positioned as and in place of the lower left-hand quarter section K, it will be found that the support ribs are arranged and positioned identically to the support ribs described in connection with the lower left-hand quarter section K when the tile is in the position of Fig. 1. And so if the rotation of the tile is continued through another 90 so that the upper right-hand quarter section N is positioned as the lower left-hand quarter section K, the arrangement and positioning of its support ribs 51, 52, 53 and 54 will be identical with that described in connection with Fig. 1. With the rotation of the tile continued through another 90 so as to place what appears in Fig. 1 as the upper left-hand quarter section M in position as and in place of the lower left-hand quarter section, then again it will be found that the set of support ribs 51, 52, 53 and 54 is identical with that hereinabove described for the set of support ribs of the lower left-hand quarter section K with the tile in the position of Fig. 1.

With this arrangement or system of the four (4) sets of support ribs for the tile of Fig. 1, it will be noted that there is an outer annular series of support ribs made up of the ribs 51, 52 and 53 in each quarter section of the rear surface 14 of tile T, and the generally concentric, inner annular row of support ribs made up of the ribs 54. Now with the support ribs so positioned and arranged in spaced and angular relationship on and over the major area of the rear surface of the tile T surrounded by the continuous edge flange F, by reference to Fig. 6 in which a pair of tiles T having such sets of support ribs are positioned back-to-back, it will be seen that in every instance the support ribs 51, 52, 53 and 54 of one tile extend across and engage at their central portions of greatest depth with the support ribs 51, 52, 53 and 54 of the other tile. Thus there is provided full and complete support for the bodies B of a pair of backto-back tiles T to thereby prevent inward springing or depressing of the bodies of these tiles under inwardly acting compressive loads applied to the outer sides thereof. And a further and important feature of this support rib system of my present invention is the fact that all of the support ribs of one tile of a pair of back-toback tiles will always cross over and engage with the support ribs of the other tile irrespective of the angular relationship around the central, transverse axes of the tiles when they are put together and assembled back-toback, just so long as the tiles are in plan alignment with the rear edges 22 of the continuous edge flanges F in alginment and abutting.

The support rib system of the example tile T provides what is now believed to be a satisfactory number of support ribs and of supported area for efiicient functioning. However, it is intended, if desired, that the number of support ribs may be reduced and, for example, concentrated in the central area only of the rear surface of the tile as by eliminating the outer support ribs 51, 52 and 53 and retaining only the inner series of support ribs 54. Conversely, if it should be desired to concentrate the support around the outermost area of the rear sur face of the tile T, these inner support ribs may be eliminated and only the ribs 51, 52 and 53 retained in their positions around the rear surface of the tile. Or the number of support ribs may be increased to any desired number in excess of the number of support ribs of the example tile of Fig. l.

The specific expression of the support rib system of my invention as disclosed in Fig. l as a preferred form, with the specific angles at which the support ribs are positioned and the specific length and thickness dimensions are not in all respects critical, although they are believed to be advantageous from the production and functioning standpoints. It will be recognized that basically a support rib system in accordance with my invention and its principles, provides support ribs at opposite sides of the transverse center lines or major axes of the plan form of a tile with such support rib-s located substantially in the same relative positions on each tile, so that when a tile is placed back-to-back with another tile the support ribs of the first tile will always be positioned extending at an angle across, that is, intersecting, the support ribs of the other tile with the rear edges of the crossed support ribs preferably in seating and tile body supporting engagement. Attention is directed to the fact that my invention contemplates and includes a support arrangement in which the support ribs instead of being angularly positioned relative to the adjacent edge flanges, may be positioned in substantial parallelism with such edge flanges, as diagrammatically indicated by the support ribs 61, 62, 63 and 64 in Fig. 7 of the draw ings. As a further example of possible support rib arrangements of my invention, reference is made to Fig. 8 in which an arrangement of support ribs 51', 52', 53' and 54' is diagrammatically illustrated as what amounts to a reversal of the positioning and angular relationships of the support ribs of the system as disclosed in Fig. l.

The system of support ribs in addition to their primary function of giving support to the bodies of back-toback tiles, also has the important feature of preventing any interlocking between ribs, ridges, or other similar projections on the rear side of the tile in the event that the tiles of a back-to-back pair move relative to each other from their proper position of alignment. Thus the support ribs 51 through 54 of the example tile T, due to the fact that tiles having such ribs when placed back-to-back and are in plan alignment will always have the support ribs of one tile located extending across and freely slidably engaging the support ribs of the other tile, cannot interlock and prevent return of the tiles to proper relative positions. Hence, with these support ribs hav ing such intersecting or crossed-over relationship with free slidable and minimum friction bearing engagement therebetween, the support ribs in cooperation with the mesh system of intersecting sealing ribs 41, make it impossible for the tiles when displaced from their proper positions of alignment to become locked in a displaced or in a canted or tilted position through interlocking engagement between the tile edge flanges and/or between the rearwardly projecting support ribs or ridges on the rear sides of the tiles.

It will also be evident that various other changes, modifications, constructions, combination, substitutions, eliminations and additions may be resorted to without departing from the broad spirit and scope of my invention and hence I do not desire or intend to limit my invention in all respects to the exact and specific examples thereof as herein disclosed, except as may be required by intended specific limitations thereto appearing in any of the claims hereto appended.

What I claim is:

1. A wall tile including, in combination, a thin body of plate form having a front side and an opposite generally planar rear side; said tile body having outer side edges therearound and a continuous edge flange integral with said outer side edges extending rearwardly therefrom relative to said tile body; a first multiplicity of generally parallel, short length sealing ribs joined at their outer ends with said continuous edge flange at the inner side of the latter; said generally parallel sealing ribs being positioned closely spaced apart along and completely around said inner side of said edge flange extending short distances inwardly therefrom transversely over the rear side of said tile body; each of said short length, substantially parallel sealing ribs being inclined at an angle laterally in the same direction relative to said edge flange; a second multis plicity of generally parallel, short length sealing ribs joined at their outer ends with said continuous edge flange at the inner side of the latter; said generally parallel sealing ribs of said second multiplicity of short length sealing ribs being positioned closely spaced apart along and completely around the inner side of said edge flange extending short distances inwardly from and transversely over the rear side of said tile body; each of said short length, generally parallel sealing ribs of said second multiplicity of sealing ribs being inclined at an angle laterally in the same direction relative to said edge flange but opposite the direction of inclination of said sealing ribs of said first multiplicity of sealing ribs; and said sealing ribs of said second multiplicity of sealing ribs extending across and intersecting sad sealing ribs, respectively, of said first multiplicity of sealing ribs forming with the latter a closed rib barrier along the inner side of said continuous edge flange completely around the rear side of said tile body between said edge flange and the rear side of said tile body surrounded thereby.

2. In the combination of claim 1, the rear edge surfaces of said crossed-over and integrally intersecting sealing ribs of said first and of said second multiplicity of sealing ribs at the outer ends thereof at said edge flange being located substantially in the plane of the rear edge of said edge flange and being inclined inwardly and forwardly from said outer ends to and merging at the inner ends thereof into said rear side of said tile body.

3. In the combination of claim 1, the sealing ribs of either said first or of said second multiplicity of said sealing ribs extending across and integrally intersecting at least two of said sealing ribs of the other of said multiplicity of said sealing ribs.

4. In the combination of claim 1, each of said sealing ribs of said first multiplicity of sealing ribs being joined at its outer end with the inner side of said edge flange at the location at which the outer end of the adjacent sealing rib of said second multiplicity of sealing ribs is joined with the inner side of said edge flange.

5. In the combination of claim 1, each of said sealing ribs of said first multiplicity of sealing ribs at its outer end being joined with the inner side of said edge flange at the location at which the outer end of a sealing rib of said second multiplicity of said sealing ribs is joined with the inner side of said edge flange; and each of said sealing ribs of said first multiplicity of sealing ribs at its inner end merging into said rear side of said body at the location thereon at which the inner end of an adjacent sealing rib of said second multiplicity of said sealing ribs merges into said rear side of said tile body.

6. In the combination of cla'nn 1, each of said sealing ribs of said first multiplicity of sealing ribs at its inner end merging intosaid rear surface of said body at the location thereon at which the inner end of a sealing rib of said second multiplicity of said sealing ribs merges into said rear side of said tile body.

7. In the combination of claim 1, said tile body being of generally rectangular plan form and said continuous edge flange being comprised of side edge flanges joined at the corners of said tile body; a corner rib extending diagonally inwardly over the rear side of said tile body from each corner of said edge flange with its outer end joined with said edge flange at said corner; cross ribs on the rear side of said tile body spaced apart along and integrally intersecting each of said corner ribs; and adjacent sealing ribs of said first and of said second multiplicity of said cross-over and intersecting sealing ribs at opposite sides of each of said corner ribs being joined with said cross ribs, respectively, in substantial longitudinal alignment therewith and continuation thereof.

8. A plastic wall tile having a relatively thin body of plate form with a continuous rearwardly extending edge flange therearound integral therewith, in combination with a continuous, unbroken rib barrier completely around the rear side of said body along and joined at its outer side with the inner side of said rearwardly extending edge flange; said rib barrier being of relatively small width and extending a relatively short distance inwardly from said edge flange over said rear side of said body; and said continuous, unbroken rib barrier being comprised of a multiplicity of closely spaced, short length sealing ribs joined at their outer ends with the inner side of said edge flange and crossing over and integrally intersecting each other along and completely around said edge flange.

9. A tile comprising, in combination, a body of plate form having a front side, an opposite rear side, and outer edges therearound joining at the corners, respectively, of said body; rearwardly extending side edge flanges along said outer side edges, respectively, integrally joined at the corners, respectively, of said body to form a continuous edge flange therearound surrounding said rear side of said tile body; a multiplicity of short length sealing ribs closely spaced along each of said side edge flanges with the outer ends thereof joined with the inner sides of said flanges; said short length sealing ribs along each side edge flange extending inwardly therefrom a short distance over said rear side of said body; said multiplicity of short length sealing ribs along each of said side edge flanges extending inwardly therefrom over said rear side of said body substantially the same distance; said multiplicity of sealing ribs along each of said side edge flanges crossing over and integrally intersecting each other; and said sealing ribs at opposite ends of each of said side edge flanges being integrally joined with said sealing ribs at adjacent ends of adjacent side edge flanges to thereby form with said multiplicity of crossed-over and intersecting sealing ribs along each side edge flange a continuous and unbroken barrier of said sealing ribs completely around the inner side of said side edge flanges and between the latter and said rear side of said body surrounded thereby.

10. A tile having a body of plate form with a continuous rearwardly extending edge flange therearound, in combination with a continuous, unbroken sealing rib barrier of small width relative to the plan dimension of the rear side of said tile body; said sealing rib barrier extending along and a short distance inwardly from said edge flange and being comprised of a plurality of arcuate ribs having their spaced outer ends integrally joined with the inner side of said edge flange and extending inwardly therefrom a short distance over said rear side of said tile body; and said multiplicity of arcuate ribs being closely spaced along said edge flange in positions crossing over and integrally intersecting adjacent of said arcuate ribs forming a continuous and unbroken rib barrier completely around said edge flange between the latter and the rear side of said body surrounded thereby.

References Cited in the file of this patent UNITED STATES PATENTS 723,979 Blackmore Mar. 31, 1903 2,156,149 Feichter Apr. 25, 1939 2,490,557 Brown Dec. 6, 1949 2,666,373 Mattson Jan. 19, 1954 2,809,544 M-accaferri Oct. 15, 1957 FOREIGN PATENTS 3,727 Great Britain of 1909 615,609 Great Britain of 1949 438,599 Great Britain Nov. 14, 1955 413,150 Italy of 1946 

